


My Latest Mistake

by ByTheAngell (SomeLittleInfamy)



Category: Shadowhunters (TV)
Genre: 3x19 Coda, Gen, M/M
Language: English
Status: Completed
Published: 2019-04-23
Updated: 2019-04-23
Packaged: 2020-01-24 08:20:30
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,615
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18567505
Author URL: https://archiveofourown.org/users/SomeLittleInfamy/pseuds/ByTheAngell
Summary: Alec doesn't know why he thought a deal with a Greater Demon wouldn't have a catch... that he could give Magnus back the life he missed without any risks, without any consequences. Witnessing them first-hand, he wonders if he made the right decision after all...





	My Latest Mistake

**Author's Note:**

> A 3x19 coda, so obvious episode spoilers ahead!

“Alec…” The voice that reaches him from his office is soft, hesitant. Alec isn’t sure if it’s because Jace is too busy tip-toeing around him over everything with Magnus, or because he’s still embarrassed over getting bested by an art student who only learned about the Shadow World a few months ago, but either way he’s tired, and isn’t sure he can deal with any more just then. 

“Can it wait?” Alec sighs, glancing down at his desk at the mountains of papers in front of him. There is no shortage of reports to file - about Isabelle’s undercover investigation into Glorious and taking down Aldertree, of Jace’s undercover operation to follow Clary and Jonathan, of the fact that they  _ lost _ Clary and Jonathan, and now have to account for the potential kidnapping of the Seelie Queen… it’s a lot. It’s too much, but at the very least it’s a distraction from the fact that his personal life has fallen to pieces around him. 

“No.” Isabelle says, coming up behind Jace. Her face is solemn, more serious than he’s seen in days, even when he first brought up Asmodeus’ ultimatum to her. 

“Look, if this is some sort of intervention, we can just skip the theatrics and--” Alec starts, only to be cut off by Jace again. 

“It’s not. But it is about Magnus.” Jace looks nervous. So does Isabelle. If this was just about him, just about his relationship, then they wouldn’t be so hesitant to barge in and try to put him in his place. He knows his siblings better than that. 

“What is it? Is he--” Alec starts, but the words fall short. He’s lost the right to ask about Magnus, to know how he’s doing, what’s going on in his life, the moment he cut things off between them. “It isn’t my business. Please, you two, I know you mean well but just--” 

“He has his magic back, but he’s with Asmodeus.” Isabelle says. 

It takes him a few moments to process that statement. That’s impossible. Asmodeus is in Edom, unless… 

“A warlock was found dead in her shop in the city. Upon further investigation there were signs of a rift opening, of stronger demonic energy than we’ve registered since Lilith. We tapped into some cameras in the city and tracked the last person to enter and leave the shop at the time of her death. He followed Magnus through the city… it’s Asmodeus. We’re sure of it.” 

Alec’s mind is blank. What happened? How did he get here? Was it something he did, something he said, that allowed him to break his banishment in Edom? Or did Magnus bring him here, calling to him in his time of need? Alone, with no one to turn to but the only family he has left? 

...did Alec drive Magnus to this? 

“Thank you for telling me, I-” but his words fall short again. He should tell the Clave. He should warn them, gather every force they have to defend against the Greater Demon the way he failed to do with Lilith… but he falters, again, the same way he had before when Jace was the one at risk. 

This isn’t what he wanted. He didn’t make a deal to get Magnus his magic back only to send him into the arms of a abusive, neglectful father. He didn’t give him his powers only to pit him against the Clave. 

“...what do you want us to do?” Jace asks, as if reading his mind. And maybe he is. Bond or not, Jace always had an uncanny ability of knowing what he’s thinking. It made them terrors at the Academy, and especially for their mother, but now he wishes nothing more than to keep his thoughts to himself. He doesn’t want anyone to know the pain he feels… or the guilt. 

“Who else knows?” Alec asks, his tone teetering carefully between hopeful and fearful. If no one knows they can cover it up, but at the same time if no one knows then it falls solely on them to decide the fate of the entire Shadow World in this moment. One gives him two choices, and the other makes the decision for him, forcing his hand. 

“Just us, and Underhill. He’s the one who tracked surveillance,” Isabelle says.

“Show me.” 

“Alec, I don’t think that’s such a good idea,” Izzy says, shooting a nervous glance in Jace’s direction.    
  
“Show me.” He repeats, and this time he’s standing up, back straight, voice stern. It isn’t a request. He needs to see the consequences of his decision. 

“...Alright.” 

It’s a quiet walk to the security room where Underhill looks both surprised and horrified to see Alec stroll in through the door. 

“He wants to see the footage,” Jace tells him, the look on his face making it very clear that this isn’t up for debate. 

“Fine. But don’t shoot the messenger,” Underhill says, rewinding a series of surveillance tapes before hitting play. 

Alec watches Magnus get his magic back, feeling some small flicker of hope for the first time all day. 

“He did it,” Alec mutters under his breath, the smallest smile flashing across his face. 

It doesn’t last long. Asmodeus tracks Magnus’ magic signature, following him at a distance to the love locks. Alec feels every last ounce of hope inside him burn away with the lock on the ground. His chest is tight and he can’t fight the tears that fall silently at the sight, remembering the words Magnus uttered before engraving them with his magic. 

The same magic that turned them to ashes now in his wake. 

It isn’t any easier to watch him meet with a Silent Brother - over what they don’t know, there’s no audio on the cameras they tap into, only images. But it’s clear that Magnus isn’t okay. It’s clear that even with his magic he’s still distraught. 

This was supposed to fix things. Magnus is supposed to be happy again. Whole again. 

What went wrong? 

They lose the cameras when Magnus disappears, only to pick them back up again with Magnus walking next to Asmodeus. There’s no magic binding him, no sign of coercion. They’re just walking, side-by-side, and when the finally come to a stop it’s for Magnus to open a portal that he patiently waits for Asmodeus to step through first before following through and closing behind them.   
  
The tape cuts out, and Alec leans forward, eager for another glimpse of the man he loves, for any sign of where Magnus is right now and proof that he’s alright. The timestamp shows this footage as within the hour.

Alec’s eyes are glued to the screen but when he finally pries them away the others in the room are all focused on him, watching and waiting for his reaction. No, more than that - they’re waiting for  _ instructions _ , because now it’s up to him what they do about his ex-boyfriend gone rogue with his Greater Demon father. 

He knows they’ll keep this quiet if Alec asks him to… but can he? What kind of leader does that make him if he does? Does he want to leave behind the legacy as the only Head of the New York Institute who habitually put the wellbeing of downworlders before that of his own people? 

Is he capable of doing anything else, when the downworlder in question is Magnus Bane? 

“Thank you for telling me.”  Alec still doesn’t know what he’s going to do.  

“I’m so sorry, Alec,” Izzy says, reaching out for him. He doesn’t fight her embrace, but he doesn’t return it, either. He doesn’t deserve the comfort, not when he’s the reason for the pain in the first place. 

“Don’t be. I made my decision. Magnus has his powers back. It’s what he wanted… it’s what he needed. What he does with them now isn’t up to me.” 

“Alec, just tell him about--”    
  
“No! I can’t, Izzy, I- I won’t. I won’t take this away from him.” 

He’s never felt so lost. So helpless. Magnus has his magic back but Alec knows the sort of person Asmodeus is. He knows what Magnus thinks of him, what he feels about him. How low must Magnus be to turn to his father for comfort? For acceptance? 

Or, Alec shudders to think, for companionship? 

“We can’t make the same mistake we did with Lilith,” Alec says, his voice resigned. “Underhill, alert the Clave about Asmodeus. This is a serious threat to the entire Shadow World… to the entire  _ world _ .” This is his fault. He was selfish. He was foolish. So eager to give Magnus what he thought he needed he played right into the hands of a Greater Demon. This couldn’t be a coincidence…. It had to be something he did. Something he missed, that allowed Asmodeus to come here now. 

How could he be so  _ stupid _ ?! 

Of course Asmodeus would swoop in as the savior, returning Magnus’ magic to him, his life, his very  _ soul _ . He played the savior at the expense of Alec’s love, and Alec let him. He practically handed Magnus over on a silver platter, abandoned and betrayed and vulnerable. 

This wasn’t Asmodeus’ doing, not entirely, Alec realizes. He’s just as much to blame. 

“Where are you going?” Jace asks, face pulled tight with concern as Alec pushes past them into the hallway. 

At least there’s one thing Alec is entirely positive of right now, in a sea of doubts. He can trust Isabelle and Jace to do what needs to be done here. The Institute can take the lead in tracking down Asmodeus. But as for him? 

His loyalties are owed elsewhere.  

“I’m going to save Magnus.” 

**Author's Note:**

> THIS IS A ONE SHOT AND THIS WEEK I'M KEEPING IT A ONE SHOT GDI
> 
> ( Find me on [Tumblr](http://bytheangell.tumblr.com) and also on [Twitter](http://www.twitter.com/By_The_Angell) while we all hang out waiting for someone to #SaveShadowhunters ! <3)


End file.
